Good nutrition is important for cancer patients.

Nutrition is a process in which food is taken in and used by the body for growth, to keep the body healthy, and to replace tissue. Good nutrition is important for good health. Eating the right kinds of foods before, during, and after cancer treatment can help the patient feel better and stay stronger. A healthy diet includes eating and drinking enough of the foods and liquids that have the important nutrients (vitamins, minerals, protein, carbohydrates, fat, and water) the body needs.

When the body does not get or cannot absorb the nutrients needed for health, it causes a condition called malnutrition or malnourishment.

This summary is about nutrition in adults with cancer.

Healthy eating habits are important during cancer treatment.

Nutrition therapy is used to help cancer patients get the nutrients they need to keep up their body weight and strength, keep body tissue healthy, and fight infection. Eating habits that are good for cancer patients can be very different from the usual healthy eating guidelines.

Healthy eating habits and good nutrition can help patients deal with the effects of cancer and its treatment. Some cancer treatments work better when the patient is well nourished and gets enough calories and protein in the diet. Patients who are well nourished may have a better prognosis (chance of recovery) and quality of life.

Cancer can change the way the body uses food.

Some tumors make chemicals that change the way the body uses certain nutrients. The body's use of protein, carbohydrates, and fat may be affected, especially by tumors of the stomach or intestines. A patient may seem to be eating enough, but the body may not be able to absorb all the nutrients from the food.

Cancer and cancer treatments may affect nutrition.

For many patients, the effects of cancer and cancer treatments make it hard to eat well. Cancer treatments that affect nutrition include:

Cancer and cancer treatments may affect taste, smell, appetite, and the ability to eat enough food or absorb the nutrients from food. This can cause malnutrition (a condition caused by a lack of key nutrients). Malnutrition can cause the patient to be weak, tired, and unable to fight infections or get through cancer treatment. Malnutrition may be made worse if the cancer grows or spreads. Eating too little protein and calories is a very common problem for cancer patients. Having enough protein and calories is important for healing, fighting infection, and having enough energy.

Anorexia and cachexia are common causes of malnutrition in cancer patients.

Anorexia (the loss of appetite or desire to eat) is a common symptom in people with cancer. Anorexia may occur early in the disease or later, if the cancer grows or spreads. Some patients already have anorexia when they are diagnosed with cancer. Almost all patients who have advanced cancer will have anorexia. Anorexia is the most common cause of malnutrition in cancer patients.

Cachexia is a condition marked by a loss of appetite, weight loss, muscle loss, and general weakness. It is common in patients with tumors of the lung, pancreas, and upper gastrointestinal tract. It is important to watch for and treat cachexia early in cancer treatment because it is hard to correct.

Cancer patients may have anorexia and cachexia at the same time. Weight loss can be caused by eating fewer calories, using more calories, or both.

It is important to treat weight loss caused by cancer and its treatment.

It is important that cancer symptoms and side effects that affect eating and cause weight loss are treated early. Both nutrition therapy and medicine can help the patient stay at a healthy weight. Medicine may be used for the following:

Ability to walk and do other activities of daily living (dressing, getting into or out of a bed or chair, taking a bath or shower, and using the toilet).

A physical exam is also done to check the body for general health and signs of disease. The doctor will look for loss of weight, fat, and muscle, and for fluid buildup in the body.

Finding and treating nutrition problems early may improve the patient's prognosis (chance of recovery).

Early nutrition screening and assessment help find problems that may affect how well the patient's body can deal with the effects of cancer treatment. Patients who are underweight or malnourished may not be able to get through treatment as well as a well-nourished patient. Finding and treating nutrition problems early can help the patient gain weight or prevent weight loss, decrease problems with the treatment, and help recovery.

A healthcare team of nutrition specialists will continue to watch for nutrition problems.

A nutrition support team will check the patient's nutritional health often during cancer treatment and recovery. The team may include the following specialists:

A patient whose religion doesn't allow eating certain foods may want to talk with a religious advisor about allowing those foods during cancer treatment and recovery.

There are three main goals of nutrition therapy for cancer patients in active treatment and recovery.

The main goals of nutrition therapy for patients in active treatment and recovery are to provide nutrients that are missing, maintain nutritional health, and prevent problems. The health care team will use nutrition therapy to do the following:

Nutrition support gives nutrition to patients who cannot eat or digest normally.

It is best to take in food by mouth whenever possible. Some patients may not be able to take in enough food by mouth because of problems from cancer or cancer treatment. Medicine to increase appetite may be used.

Nutrition support for patients who cannot eat can be given in different ways.

Nutrition support can improve a patient's quality of life during cancer treatment, but there are harms that should be considered before making the decision to use it. The patient and health care providers should discuss the harms and benefits of each type of nutrition support. (See the Nutrition in Advanced Cancer section below for more information on deciding whether to use nutrition support.)

Enteral Nutrition

Enteral nutrition is also called tube feeding.

Enteral nutrition is giving the patient nutrients in liquid form (formula) through a tube that is placed into the stomach or small intestine. The following types of feeding tubes may be used:

A nasogastric tube is inserted through the nose and down the throat into the stomach or small intestine. This kind of tube is used when enteral nutrition is only needed for a few weeks.

A gastrostomy tube is inserted into the stomach or a jejunostomy tube is inserted into the small intestine through an opening made on the outside of the abdomen. This kind of tube is usually used for long-term enteral feeding or for patients who cannot use a tube in the nose and throat.

The type of formula used is based on the specific needs of the patient. There are formulas for patients who have special health conditions, such as diabetes. Formula may be given through the tube as a constant drip (continuous feeding) or 1 to 2 cups of formula can be given 3 to 6 times a day (bolus feeding).

Enteral nutrition is sometimes used when the patient is able to eat small amounts by mouth, but cannot eat enough for health. Nutrients given through a tube feeding add the calories and nutrients needed for health.

Enteral nutrition may continue after the patient leaves the hospital.

If enteral nutrition is to be part of the patient's care after leaving the hospital, the patient and caregiver will be trained to do the nutrition support care at home.

Parenteral Nutrition

Parenteral nutrition is used when the patient cannot take food by mouth or by enteral feeding. Parenteral feeding does not use the stomach or intestines to digest food. Nutrients are given to the patient directly into the blood, through a catheter (thin tube) inserted into a vein. These nutrients include proteins, fats, vitamins, and minerals.

Parenteral nutrition is used only in patients who need nutrition support for five days or more.

The catheter may be placed into a vein in the chest or in the arm.

A central venous catheter is placed beneath the skin and into a large vein in the upper chest. The catheter is put in place by a surgeon. This type of catheter is used for long-term parenteral feeding.

A peripheral venous catheter is placed into a vein in the arm. A peripheral venous catheter is put in place by trained medical staff. This type of catheter is usually used for short-term parenteral feeding.

The patient is checked often for infection or bleeding at the place where the catheter enters the body.

Parenteral nutrition support may continue after the patient leaves the hospital.

If parenteral nutrition is to be part of the patient's care after leaving the hospital, the patient and caregiver will be trained to do the nutrition support care at home.

Ending parenteral nutrition support must be done under medical supervision.

Going off parenteral nutrition support needs to be done slowly and is supervised by a medical team. The parenteral feedings are decreased by small amounts over time until they can be stopped, or as the patient is changed over to enteral or oral feeding.

Surgery to the head, neck, esophagus, stomach, or intestines may affect nutrition.

Most cancer patients are treated with surgery. Surgery that removes all or part of certain organs can affect a patient's ability to eat and digest food. The following are nutrition problems caused by specific types of surgery:

It is common for patients to have pain, tiredness, and/or loss of appetite after surgery. For a short time, some patients may not be able to eat what they usually do because of these symptoms. Following certain tips about food may help. These include:

Stay away from carbonated drinks (such as sodas) and foods that cause gas, such as:

Beans.

Peas.

Broccoli.

Cabbage.

Brussels sprouts.

Green peppers.

Radishes.

Cucumbers.

Increase calories by frying foods and using gravies, mayonnaise, and salad dressings. Supplements high in calories and protein can also be used.

Choose high-protein and high-calorie foods to increase energy and help wounds heal. Good choices include:

Eggs.

Cheese.

Whole milk.

Ice cream.

Nuts.

Peanut butter.

Meat.

Poultry.

Fish.

If constipation is a problem, increase fiber by small amounts and drink lots of water. Good sources of fiber include:

Chemotherapy and Nutrition

Chemotherapy affects cells all through the body.

Chemotherapy affects fast-growing cells and is used to treat cancer because cancer cells grow and divide quickly. Healthy cells that normally grow and divide quickly may also be killed. These include cells in the mouth, digestive tract, and hair follicles.

Chemotherapy may affect nutrition.

Chemotherapy may cause side effects that cause problems with eating and digestion. When more than one anticancer drug is given, more side effects may occur or they may be more severe. The following side effects are common:

Nutrition therapy can help relieve nutrition problems caused by chemotherapy.

Patients who have side effects from chemotherapy may not be able to eat normally and get all the nutrients they need to restore healthy blood counts between treatments. Nutrition therapy can help relieve these side effects, help patients recover from chemotherapy, prevent delays in treatment, prevent weight loss, and maintain general health. Nutrition therapy may include the following:

Radiation therapy may affect nutrition.

Radiation therapy to any part of the digestive system often has side effects that cause nutrition problems. Most of the side effects begin a few weeks after radiation therapy begins and go away a few weeks after it is finished. Some side effects can continue for months or years after treatment ends.

Radiation therapy may also cause tiredness, which can lead to a decrease in appetite.

Nutrition therapy can help relieve the nutrition problems caused by radiation therapy.

Nutrition therapy during radiation treatment can help the patient get enough protein and calories to get through treatment, prevent weight loss, help wound and skin healing, and maintain general health. Nutrition therapy may include the following:

The side effects of biologic therapy can cause weight loss and malnutrition if they are not treated. Nutrition therapy can help patients receiving biologic therapy get the nutrients they need to get through treatment, prevent weight loss, and maintain general health.

Stem Cell Transplant and Nutrition

Stem cell transplant patients have special nutrition needs.

Chemotherapy, radiation therapy, and medicines used for a stem cell transplant may cause side effects that keep a patient from eating and digesting food as usual. Common side effects include the following:

Patients who have a transplant need plenty of protein and calories to get through and recover from the treatment, prevent weight loss, fight infection, and maintain general health. It is also important to avoid infection from bacteria in food. Nutrition therapy during transplant treatment may include the following:

A diet of cooked and processed foods only, because raw vegetables and fresh fruit may carry harmful bacteria.

Guidelines on safe food handling.

A specific diet based on the type of transplant and the part of the body affected by cancer.

Parenteral nutrition (feeding through the bloodstream) during the first few weeks after the transplant, to give the patient the calories, protein, vitamins, minerals, and fluids they need to recover.

Treatment of Symptoms

Key Points for This Section

When side effects of cancer or cancer treatment affect normal eating, changes can be made to help the patient get the nutrients needed. Medicines may be given to increase appetite. Eating foods that are high in calories, protein, vitamins, and minerals is usually best. Meals should be planned to meet the patient's nutrition needs and tastes in food. The following are some of the more common symptoms caused by cancer and cancer treatment and ways to treat or control them.

Anorexia

Anorexia (the loss of appetite or desire to eat) is one of the most common problems for cancer patients. Eating in a calm, comfortable place and getting regular exercise may improve appetite. The following may help cancer patients who have a loss of appetite:

Eat small high-protein and high-calorie meals every 1-2 hours instead of three large meals. The following are high-calorie, high-protein food choices:

Taste Changes

Changes in how foods taste may be caused by radiation treatment, dental problems, mouth sores and infections, or some medicines. Many cancer patients who receive chemotherapy notice a bitter taste or other changes in their sense of taste. A sudden dislike for certain foods may occur. This can cause a loss of appetite, weight loss, and a decreased quality of life. Some or all of a normal sense of taste may return, but it may take up to a year after treatment ends. The following may help cancer patients who have taste changes:

Dry Mouth

Dry mouth is often caused by radiation therapy to the head and neck and by certain medicines. Dry mouth may affect speech, taste, and the ability to swallow or to use dentures or braces. There is also an increased risk of cavities and gum disease because less saliva is made to wash the teeth and gums.

The main treatment for dry mouth is drinking plenty of liquids. Other ways to help relieve dry mouth include the following:

Keep water handy at all times to moisten the mouth.

Eat moist foods with extra sauces, gravies, butter, or margarine.

Eat foods and drinks that are very sweet or tart (to increase saliva).

Mouth Sores and Infections

Mouth sores can be caused by chemotherapy and radiation therapy. These treatments affect fast-growing cells, such as cancer cells. Normal cells inside the mouth also grow quickly and may be damaged by these cancer treatments. Mouth sores can be painful and become infected or bleed and make it hard to eat. By choosing certain foods and taking good care of their mouths, patients can usually make eating easier. The following can help patients who have mouth sores and infections:

Eat soft foods that are easy to chew and swallow, such as the following:

Low White Blood Cell Counts and Infections

A low white blood cellcount may be caused by radiation therapy, chemotherapy, or the cancer itself. Patients who have a low white blood cell count have an increased risk of infection. The following may help cancer patients prevent infections when white blood cell counts are low:

Thaw foods in the refrigerator or microwave. Never thaw foods at room temperature. Cook foods immediately after thawing.

Keep hot foods hot and cold foods cold.

Cook all meat, poultry, and fish until well done.

Refrigerate all leftovers within 2 hours of cooking and eat them within 24 hours.

Buy foods packed as single servings, to avoid leftovers.

Do not buy or eat food that is out of date.

Do not buy or eat food in cans that are swollen, dented, or damaged.

Dehydration (Lack of Fluid)

The body needs plenty of water to replace the fluids lost every day. Nausea, vomiting, and pain may keep the patient from drinking and eating enough to get the amount of water the body needs. Long-term diarrhea causes a loss of fluid from the body. One of the first signs of dehydration (lack of water in the body) is feeling very tired. The following may help cancer patients prevent dehydration:

Drink 8 to 12 cups of liquids a day. This can be water, juice, milk, or foods that have a lot of liquid in them, such as ice pops, flavored ices, and gelatins.

Stay away from drinks that have caffeine in them, such as sodas, coffee, and tea (both hot and cold).

Take a water bottle whenever leaving home. It is important to drink even if not thirsty.

Drink most liquids between meals.

Use medicines that help prevent and treat nausea and vomiting.

Constipation

It is very common for cancer patients to have constipation (fewer than three bowel movements a week). Constipation may be caused by the following:

Certain medicines used to treat the side effects of chemotherapy, such as nausea and pain.

Preventing and treating constipation is a part of cancer care.

To prevent constipation:

Eat more fiber-containing foods. Twenty-five to 35 grams of fiber a day is best. Food labels show the amount of fiber in a serving. (Some sources of fiber are listed below.) Add a little more fiber each day and drink plenty of fluids at the same time to keep the fiber moving through the intestines.

Drink 8 to 12 cups of fluid each day. Water, prune juice, warm juices, lemonade, and teas without caffeine can be very helpful.

Take walks and exercise regularly. Wear shoes made for exercise.

To treat constipation:

Continue to eat high-fiber foods and drink plenty of fluids. Try adding wheat bran to the diet; begin with 2 heaping tablespoons each day for 3 days, then increase by 1 tablespoon each day until constipation is relieved. Do not take more than 6 tablespoons a day.

Nutrition needs are different for patients with advanced cancer.

It is common for patients with advanced cancer to want less food. Patients usually prefer soft foods and clear liquids. Those who have problems swallowing may do better with thick liquids than with thin liquids. Patients often do not feel much hunger at all and may need very little food.

In patients with advanced cancer, most foods are allowed. During this time, eating can be focused on pleasure rather than getting enough nutrients. Patients usually cannot eat enough of any food that might cause a problem. However, some patients may need to stay on a special diet. For example, patients with cancer that affects the abdomen may need a soft diet to keep the bowel from getting blocked.

The benefits and harms of nutrition support are different for each patient.

Answering the following questions may help to make decisions about using nutrition support:

What are the wishes and needs of the patient and family?

Will the patient's quality of life be improved?

Do the possible benefits outweigh the risks and costs?

Is there an advance directive? An advance directive is a legal document that states the treatment or care a person wishes to receive or not receive if he or she becomes unable to make medical decisions. One type of advance directive is a living will.

Cancer patients and their caregivers have the right to make informed decisions. The healthcare team and a registered dietitian can explain the benefits and risks of using nutrition support for patients with advanced cancer. In most cases, there are more harms than benefits, especially with parenteral nutrition support. However, for someone who still has good quality of life but is unable to get enough food and water by mouth, enteral feedings may be best. The benefits and risks of enteral nutrition during advanced cancer include the following:

Food and Drug Interactions

Key Points for This Section

Some foods do not mix safely with certain drugs.

Cancer patients may be treated with a number of drugs. Taking certain foods and drugs together may decrease or change how well the drugs work or cause life-threatening side effects. The following table lists some of the food and drug interactions that may occur with certain anticancer drugs:

Some herbal supplements do not mix safely with certain drugs or foods.

Taking some herbal supplements with certain foods and drugs may change how well cancer treatment works or cause life-threatening side effects. Talk with your doctor about how herbal supplements may affect your cancer treatment.

Nutrition and Lifestyle in Cancer Survivors

Key Points for This Section

Cancer survivors have special nutrition needs.

Everyone needs a healthy diet and exercise for good health and to help prevent disease. Cancersurvivors have special health needs, especially because of the risks of late effects and the cancer coming back. Studies have shown that a healthy diet helps to prevent late effects such as obesity, heart disease, and metabolic syndrome. Researchers are also studying whether certain diet and exercise habits in cancer survivors can keep cancer from coming back or keep new cancers from forming.

Healthy diet and lifestyle habits can improve the quality of life for cancer survivors.

Surveys show that many cancer survivors do not follow cancer prevention guidelines and have lifestyle behaviors that may increase their risk for late effects or make late effects worse. Education programs can help cancer survivors learn how to make behavior changes that keep them healthier. Programs that cover diet, exercise, and stress management are more likely to help cancer survivors make lasting changes.

The effect of soy on breast cancer and breast cancer prevention is being studied.

Study results include the following:

Some studies show that eating soy may decrease the risk of having breast cancer.

Taking soy supplements in the form of powders or pills has not been shown to prevent breast cancer.

Adding soy foods to the diet after being diagnosed with breast cancer has not been shown to keep the breast cancer from coming back.

Soy has substances in it that act like estrogen in the body. Studies were done to find out how soy affects breast cancer in patients who have tumors that need estrogen to grow. Some studies have shown that soy foods are safe for women with breast cancer when eaten in moderate amounts as part of a healthy diet.

If you are a breast cancer survivor be sure to check the most up-to-date information when deciding whether to include soy in your diet.

Current Clinical Trials

Check NCI’s list of cancer clinical trials for U.S. supportive and palliative care trials about malnutrition, nutritional support and nutritional therapy that are now accepting participants. The list of trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

Changes to This Summary (12/05/2014)

The PDQcancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Editorial changes were made to this summary.

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